You must to use either server script languages such as ASP/PHP
here is a PHP example http://www.tutorialguide.net/php_contact_form_tutorial.html
here is a ASP example
http://www.tizag.com/aspTutorial/aspFormsEmail.php
or you can use just form with target mailto to force send the email in Outlook, but server side scripting is better.
<form enctype="text/plain" method="get" action="mailto:info@info.com">
To <input type="text" name="To"/>
Subject <input type="text" name="Subject"/>
Body <textarea name="Body" rows="5" cols="20" wrap="physical" >
</textarea>
<input type="submit" />
</form>